Recovery of nicotine



Patented July 15, 1930 UNETEDJSTATES FF C nnnm'xfrvrcconunnn or nronnonn, VIRGINIA, nssreuon To TQBAGCO BY rnonuors & CHEMICAL eonronarion, A eonrona'rron or DELAWARE r l nnoovEnY or nroorrnn j No Drawing.

This invention relates to improvements in 'processcstor the recovery of nicotine'trom itscompounds and especiallytrom its salts.

While many ways are known forthe recover of nicotine from its salts, all of them so far as I am aware, are in the nature of purely laborator arocesses ivin a low return un- I one specific process WlllChlS the best embodiment of the invention now known to me, H

1 The starting material is a suitable; compound containing nicotine such as, for example, a salt or salts otnicoti-ne. Generally such a salt as the sulphate, chloride, acetate ornitrate of nicotine, isavailable. Usually the nicotine sulphateis most readily obtained in large quantities, and I therefore describe the specific process employingnicotine sul-' phate as the starting material, it beingunderstood, however, thatthe other salts may be used instead of the sulphate. v V p v 1 The nicotine sulphate is usually in the form of an aqueous solution and generally of about 40% strength by weight. If stronger than this, itmay Well be diluted to bring itto this strength, or if Weaker it may be evaporated,

for example, in a vacuum the said strength. 7

To ten parts by weight of this solut on of pan, to bring it," to

40% strength, I add 2 parts by weight,

of freshly V hydratedlime in powder, form (Ca(OI-I-) and then thoroughly stir'or agitate themixture. This is bestfdone by grind ing the mixture. for example,'ina ball or pebble mill. By theuse of the pebble mill running at a normal speed the mixing can be done in about ten minutes. i

Then Iadd to themixture acarbonate or hydroxid of an alkali metal. In the commercial practice I- havefound that a good soda ash isparticularly suitable. When using sodaash, I add it in, the proportion ot 1, to 7 Application filed November 29, 1921. seriernogs s pes.

parts by. weight to the above mixture and then agitate or stir it Well.

When the ball or pebblemillis-used as above described, the soda ash may be added to the mixture in the mill, after the first grinding, and then a further grinding step carried out for a short time, so as to-thoroughly incorporate the soda ash. Usually five minutes will suflice for this. At the end of this mixing the product is usually a semisolid material of such a consistency that it WlllliOlCl the pebbles in an upright position. Then Iadd to the ma terial in the mill about five parts byWeight ofwater and again agitate to form a fairly homogeneous mixture. Usually about 3 minutes moreissuflicient. This gives a product of sufiicient fluidity to flow Well so that the Whole contents of the-mill including the 'pebe bles may be readily emptied-into a vessel in which it may stand Very quickly, in fact almost. immediately, astratification takes place. A layer consisting of an aqueous, solution of' free nicotine suificiently concentrated for the usual commercial purposes, viz, from about 63 to 70% of nicotine, risesto the top of the vessel, showing a sharp plane of demarcation between itself and the under layer. In regular practice, carryingout the process on a commercial scale, I haverecovered in this top layer 81% of the original amount of the nicotine in th'est'arting material. A V

Beneath thetop layeriof concentrated aqueous solution of freenicotine is an aqueous the lime sludge." r v The nicotine solution forming the top layer may be drawn oft in any suitable way so as not tolunnecessarily agitate the stratified solutions. This maybe done by siphoning oil solution ofsodium carbonate, and below this it off through a cock locatedat an appropriate level in the side ofthe vessel, or through several such cocks at diflerent levels, as will ,bewellunderstoodbychemists.

the solution: oit'free: nicotine, or by drawing v free nicotine is slightly soluble in the soda ash solution, and this is the reason, at least in part, why the entire amount of free nicotine is not recovered in the top layer. Also, some of the nicotine will be found in the lime sludge at the bottom of the settling vessel.

Therefore, to reduce the loss, I-have found that the solution of sodium bicarbonate or sodaash may be used instead of or at least to replace some of the waterffor asucceeding batch of material, thus reducing the loss of nicotine. Preferab y the solution of sodaash is combined with water in the proportion of 9 parts of solution to 1 ,part of water. Furthermore, by washing the lime sludge with water, the freenicotine of :the sludge will be carried into solution in the water and this solution may be used-instead of pure water for the succeeding batch. 'Still better, both steps may be combined,that is, both the solution of nicotine from the sludge washing step and the solution of sodium bicarbonate may be used instead of pure water for the subsequent batch. By this means I have succeeded in reducing materially the loss of free nicotine and have been able to make recoveries as high as 86% of thenicotine in the starting material.

lVhile I have described the process particularly with reference to theme of hydrated lime, it is to be understood that barium hydroxide may be used in place of the hydrated lime. Furthermore, instead of soda ash I may use caustic soda, potassium carbonate or potassium nitrate.

A very important warning isnecessary, however, as to the addition of the soda ash or its equivalent, and that is, that it should be used in the solid state and not dissolved in water and then added, for this seems'to interfere with the success of the process.

It will be seen from the above description, that the process is a rapid one and is simple enough to be carried out on a large scale with ordinary care and without the services of skilled chemists.

The free nicotine solution as obtained from the process described is ready to go on the market. If, however, it is desired to concentrate or purify it further, this can be done by the usual methods heretofore employed for refining nicotine.

It will be apparent to those skilled in the art, that in my process, the calcium or barium of the'hydroxides used by me are metals capable of forming a water-insoluble compound or salt withthe acid of the nicotine salt, so that such salt precipitates' from the solution. Hence, in carrying out the process in the best way,'at least enough of such a hydroxide shou'ld be used a-s to-insure the presence of a combining weight of "such hydroxide.. a 1

On the other hand,the compound of the alkali metal. is Water-soluble'and therefore tends to take the water from the nicotine solution, does notreact with the nicotine and is not soluble in the strong nicotine solution, while furthermorethe free nicotine is but slightly soluble in the solution of the compound of alkali metal. Furthermore, the amount of such compound'of the alkali metal is such as to form a solution with a considerable amount of the water in the original solution of nicotine saltas well as with the watersubsequently added, thereby insuring a concentrated solution of free nicotine.

What is claimed is:

1. The processof recovering nicotine from solutions of its compounds containing an acid radical, which consists in mixing with the solution a hydroxide of a metal which will free the nicotine from its compound and unite with the acid radical to form a waterinsoluble body, then combining with the mixture a water-soluble compound of an alkali metal, then adding a-liquid comprising water in sufiicient quantity to provide a layer of said liquid whose level is above the level of the layer of solids accumulated in the process, then allowing the mixture to stand until a layer of nicotine solution accumulates at the top, and thenremoving this solution.

2. The process of'recovering nicotine from a solution of its salts, which consists in thoroughly incorporating, with said solution, a hydroxide of a metal capable of forming a water-insoluble compound with the acid of the nicotine salt, the amount of the hydroxide being suflicientto combine with all of the acid present in thenicotine salt, then incorporating a water-soluble compound in solid form which will form an aqueous solution whose density is greater than that of the nicotine solution and "in which the nicotine is practically insoluble, said compound being one 'which will not react with the nicotine, the amount of said compound added being not more than sufficientto form a saturated solution with all the water finally present in the mixture, then adding a liquid comprising water, in suflicient quantity, to form with the precedingmixture a fluid mass which can be poured from one vessel to'another, then allowing this fluid mass to stand until Stratification takes place with the nicotine solution at the top,'and the-n removing the nicotine solution. 7

3. The process of recovering nicotinefrom solutions of its salts, which consists in' mixing with the solution a. hydroxide of a metal which forms a water-insoluble salt with the acid of the nicotine salt, then combining with the mixture. an undissolved water-soluble compound of an alkali metal, then adding water'in sufficient quantity to provide a layer of water whose level is'above the layer of solids accumulatedin the-process, then allowing the'mixture to stand 'untilit'stratifies the total amount of water is sufiicient to form a layer whose level is above the layer of solids ture to stand until the concentrated nicotine solution separates, and then withdrawing the separated nicotine solution.

5. The process of recovering nicotine from its salts containing an acid radical which forms an insoluble salt with calcium, which consists in adding about 2% parts by weight of hydrated lime to 10 parts by weight of an aqueous solution of the nicotine salt of about 10% strength by weight, agitating the mixture, then adding 1 to 1 5 parts by weight of soda ash, agitating the mixture further, then adding about 5 parts by weight of water, again agitating, then allowing the mixture to stand until the nicotine solution rises to the top, and then withdrawing the nicotine 'solution.

6. The process of recovering nicotine from 7 its salts containing an acid radical which forms an insoluble saltwit-h calcium, which consists in thoroughly incorporating about 2 parts by weight of hydrated lime with 10 parts by weight of an aqueous solution of a nicotine salt of about 40% strength by weight, then incorporating about 1 to 1 parts by weight of soda ash, then mixing containing soda-ash, and employing the latter in carrying out the above set forth process with another batch of nicotine salts.

8. In the processof recovering nicotine from its salts, set forth in claim 5, the steps of removing the lime sludge from the bottom of the settling vessel, washing the sludge with water to. dissolve any free nicotine contained in said sludge and using this nicotine solu tion 'insteadof pure water in carrying out the process of claim 5 on a subsequent batch of nicotine solution. r accumulated 1n the process, allowing the mix- 9. In the process of recovering nicotine from its salts, set forth in claim 5, the steps of removing the soda-ash solution, then removing the lime sludge from the bottom of my hand. HENRY K. MoCONNELL.

about 5 parts by weight of water, allowing f the mixture to stand until stratification occurs, drawing oil the nicotine solutlon at the top, separately drawingofi' the soda-ash a solution, and using the latter solution in place of water for the treatment of a succeeding batch in accordance with the above recited.

steps.

7. The process of recovering nicotine from its salts containing an acid radical which forms an insoluble'salt with calcium, which consists in thoroughly incorporating about 2 parts by weight of hydrated lime with 10 parts by weight of an aqueous solution of a nicotine salt of about 40% strength by weight, then incorporating about 1 to 1 parts by weight of soda-ash, then adding about 9 parts by weight of a soda-ashsolu-' 1 tion obtained from a preceding use of the process and containing some freenicotine,

together with 1 partof water, then allowing the mixture to stand until it stratifies with the concentrated solution of nicotine at the top and a layer of solution containing soda ash beneath it, withdrawing the nicotine solution, separately withdrawing the solution 

